second coordination sphere
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Two novel coordination compounds containing heterocyclic bidentate N,N-donor ligand 2-(furan-2-yl)-5-(pyridin-2-yl)-1,3,4-oxadiazole (fpo) were synthesized. A general formula for compounds originating from perchlorates of iron, cobalt, and fpo can be written as: [M(fpo)2(H2O)2](ClO4)2 (M = Fe(II) for (1) Co(II) for (2)). The characterization of compounds was performed by general physico-chemical methods-elemental analysis (EA), Fourier transform infrared spectroscopy (FT-IR), nuclear magnetic resonance (NMR) in case of organics, and single crystal X-ray diffraction (sXRD). Moreover, magneto-chemical properties were studied employing measurements in static field (DC) for 1 and X-band EPR (Electron paramagnetic resonance), direct current (DC), and alternating current (AC) magnetic measurements in case of 2. The analysis of DC magnetic properties revealed a high spin arrangement in 1, significant rhombicity for both complexes, and large magnetic anisotropy in 2 (D = -21.2 cm-1). Moreover, 2 showed field-induced slow relaxation of the magnetization (Ueff = 65.3 K). EPR spectroscopy and ab initio calculations (CASSCF/NEVPT2) confirmed the presence of easy axis anisotropy and the importance of the second coordination sphere.
- MeSH
- anizotropie MeSH
- elektronová paramagnetická rezonance MeSH
- furany chemie MeSH
- kobalt chemie MeSH
- komplexní sloučeniny chemie MeSH
- krystalografie rentgenová MeSH
- magnetická rezonanční spektroskopie MeSH
- molekulární modely MeSH
- oxadiazoly chemie MeSH
- spektroskopie infračervená s Fourierovou transformací MeSH
- spektroskopie Mossbauerova MeSH
- železnaté sloučeniny chemie MeSH
- železo chemie MeSH
- Publikační typ
- časopisecké články MeSH
A new phosphinic-acid DOTA-like ligand, DO3AP(BP), containing a geminal bis(phosphonic acid) moiety as a highly effective bone-seeking group, was synthesized in high yield. Its crystal structure was determined by X-ray analysis. Complexation with lanthanide(iii) ions occurs under mild conditions (pH = 8-9, 25 degrees C, 2-3 h). (1)H, (31)P, and (17)O NMR spectroscopy show that DO3AP(BP) forms nine-coordinated lanthanide(iii) complexes with one water molecule in the first coordination sphere except for Ln = Er-Lu, which have in addition a species without lanthanide(iii)-bound water. Selective formation of only two diastereomers (out of four possible) suggests that the coordinated phosphinate phosphorus atom occurs exclusively in one of the enantiomeric forms. The ratio of the twisted square antiprism (TSA) and square antiprism (SA) diastereomers changes along the lanthanide series; the gadolinium(iii) complex has about 35% of the TSA species. The bis(phosphonate) moiety remains free for anchoring to osseous tissue. The (1)H longitudinal relaxivity of the Gd-DO3AP(BP) complex (r(1) = 7.4 s(-1) mM(-1), 20 MHz, 25 degrees C, pH = 7.5) is unexpectedly high compared to that of other monohydrated chelates of similar size thanks to a significant contribution from the second hydration sphere. The water residence time tau(M)(298) is 198 ns. Further increase in the relaxivity was observed in the presence of Zn(ii), Mg(ii) or Ca(ii) ions, due to formation of coordination polymers. Slowing down of the tumbling rate of the Gd-DO3AP(BP) complex upon adsorption on hydroxyapatite also leads to an increase of the relaxivity (r(1) = 17 s(-1) mM(-1), 20 MHz, 25 degrees C, pH = 7.5).
- MeSH
- chelátory chemie MeSH
- diagnostické zobrazování metody MeSH
- financování organizované MeSH
- gadolinium chemie MeSH
- heterocyklické sloučeniny monocyklické chemie MeSH
- hydroxyapatit MeSH
- kalcinóza patologie radiografie radioterapie MeSH
- kontrastní látky chemie MeSH
- kosti a kostní tkáň cytologie metabolismus MeSH
- krystalografie rentgenová MeSH
- lanthanoidy chemie MeSH
- molekulární struktura MeSH
- organofosfonáty chemie MeSH
Two new macrocyclic DOTA-like chelates containing one phosphonate pendant arm were synthesised as potential contrast agents for MRI (magnetic resonance imaging). The chelates bind to the lanthanide(III) in an octadentate manner, via four nitrogen atoms, three carboxylate and one phosphonate oxygen atoms. Solution structures of [Ln(do3ap(OEt2))(H(2)O)] and [Ln(do3ap(OEt))(H(2)O)](-) were studied using (31)P and (1)H NMR spectroscopy and SAP (square-antiprismatic)/TSAP (twisted square-antiprismatic) isomerism was observed. Depending on the nature of the lanthanide(III) ion, the lanthanide(III) complexes of H(4)do3ap(OEt) are present in solution as up to four different diastereoisomers observable with NMR. The TSAP isomer is the most abundant at the beginning of the lanthanide series and, with a decrease of the ionic radius of lanthanide(III) ions, both TSAP and SAP forms were observed. A second interconversion (SAP<-->TSAP') becomes important at the end of the series (TSAP' means the TSAP species without a coordinated water molecule). The remaining axial coordination site is occupied by one water molecule for the Gd(3+)-complex. The calculated fraction of the TSAP isomer in the gadolinium(III) complexes increases in the order [Gd(DOTA)(H(2)O)](-) < [Gd(do3ap(OEt2))(H(2)O)] < [Gd(do3ap(OEt))(H(2)O)](-) < [Gd(do3ap)(H(2)O)](2-). Gadolinium(III) complexes of phosphorus-containing chelates, generally, have the advantage of a relatively fast water exchange rate due to a greater sterical demand of the phosphorus acid moiety and of the presence of the second-sphere water shell, which also contributes to the overall relaxivity. The [Gd(do3ap(OEt2))(H(2)O)] and [Gd(do3ap(OEt))(H(2)O)](-) complexes were studied by variable-temperature (17)O NMR and (1)H NMRD. The experimental data were evaluated simultaneously with commonly used equations based on Solomon-Bloembergen-Morgan approximation, extended by a contribution of the second coordination sphere. The water exchange rates were found to be strongly dependent on the TSAP/SAP isomeric ratio and the overall charge of the complex: the monoanionic [Gd(do3ap(OEt))(H(2)O)](-) complex with TSAP molar fraction equal to 0.36 has the water exchange rate of 20 x 10(6) s(-1) (tau(M) = 50 ns) while neutral [Gd(do3ap(OEt2))(H(2)O)] complex with TSAP molar fraction 0.28 has an exchange rate equal to 4.4 x 10(6) s(-1) (tau(M) = 227 ns).
- MeSH
- financování organizované MeSH
- gadolinium chemie MeSH
- heterocyklické sloučeniny monocyklické chemie MeSH
- kontrastní látky chemická syntéza MeSH
- magnetická rezonanční spektroskopie metody MeSH
- molekulární modely MeSH
- molekulární struktura MeSH
- organofosfonáty chemie MeSH
- organokovové sloučeniny chemická syntéza MeSH
- roztoky MeSH
- voda chemie MeSH
... The dielectric constant of water 81 -- 5.2 The electric field and voltage of a charged conducting sphere ... ... macroscopic scale 248 -- References 250 -- Appendix 1: Mathematics 251 -- A1.1 Cartesian and polar coordinates ... ... introduction to thermodynamics and the chemical potential 270 -- A3.1 The first law 270 -- A3.2 The second ...
xii, 286 s.
... Contents -- Preface to the Third Edition (2007) xi -- Preface to the Second Edition (1992) xiv -- Preface ... ... 776 -- 15.2 Fitting Data to a Straight Line 780 -- 15.3 Straight-Line Data with Errors in Both Coordinates ... ... Control for Runge-Kutta 910 -- 17.3 Richardson Extrapolation and the Bulirsch-Stoer Method 921 -- 17.4 Second-Order ... ... Integral Equations and Inverse Theory 986 -- 19.0 Introduction 986 -- 19.1 Fredholm Equations of the Second ... ... Triangles in Two and Three Dimensions 1111 -- 21.4 Lines, Line Segments, and Polygons 1117 -- 21.5 Spheres ...
3rd ed. xxi, 1235 s. : il. ; 27 cm + 1 CD-ROM
- MeSH
- matematické výpočty počítačové MeSH
- matematika MeSH
- numerická analýza pomocí počítače * MeSH
- Publikační typ
- monografie MeSH
... INTRODUCTION 19 -- 1 CURVES AND SURFACES IN EUCLIDEAN SPACES 23 -- 1.1 Vector functions 23 -- 1.1.1 Coordinates ... ... Surfaces in Euclidean space 31 -- 1.3.1 Surfaces and simple surfaces (patchs) 31 -- 1.3.2 First and second ... ... systems and reconstructions 122 -- 3.4.1 Affine coordinates and flat manifolds 122 -- 3.4.2 Geodesic ... ... coordinates in a point, Fermi and Riemann coordinates 122 -- 3.4.3 Pre-semigeodesic coordinates 124 ... ... in Riemannian spaces 147 -- 4.3.1 Normal coordinates 147 -- 4.3.2 Coordinates generated by a system ...
1. elektronické vydání 1 online zdroj (676 stran)
VÝCHODISKA: Druhá etapa projektu IMPALA se opírala zejména o širokou diskusi týkající se problematiky zlepšování místních infrastruktur pro volnočasovou pohybovou aktivitu z praktického a konkrétního hlediska, které představovali pozvaní účastníci ze všech regionů ČR. Jedním z východisek realizace projektu IMPALA bylo zjištění některých odborných studií, že fyzické prostředí zejména u dospělé populace přispívá k nárůstu pohybové aktivity. CÍLE: Cílem prezentované části projektu IMPALA je představit konkrétní diskutované problémy z oblasti národních politik, plánování, výstavby, fi nancování a řízení infrastruktur pro volnočasovou aktivitu. METODIKA: Debata se uskutečnila v rámci národního workshopu, který se konal v červnu 2010 na akademické půdě Fakulty tělesné kultury UP v Olomouci, a měla přesně strukturovaný program, který byl připraven hlavním koordinátorem projektu. Diskuse se konala nejdříve v menších skupinkách podle jednotlivých oblastí (plánování, výstavba, fi nancování a řízení) se zaměřením na vyhodnocení současného stavu a poté na návrhy, jaké existují možnosti zlepšování. Následné společné hlavní závěry byly všemi zúčastněnými připomínkovány tak, aby nezůstaly opomenuty žádné důležité fakta z daných oblastí, nebo konkrétní praktické příklady. VÝSLEDKY: Největším problémem v oblasti plánování se jeví neexistence externí nebo interní evaluace plánovacích procesů. V oblasti výstavby je problémem dostupnost infrastruktur zejména v malých obcích; neberou se v úvahu sociálně-územní aspekty a budování také ovlivňuje vlastnictví pozemků. Financování místních infrastruktur pro volnočasovou pohybovou aktivitu je velmi široké, od veřejných zdrojů k privátním, a to v i v různých obchodních variantách. Existující modely fi nancování jsou zabezpečeny právními kontrakty a berou se v úvahu i náklady na provoz. Co se týká řízení infrastruktur, je odlišné podle vlastníka, podle zdroje fi nancování i podle typu infrastruktury. Přílišná preference vrcholového sportu znamená vyšší alokaci fi nančních prostředků zejména do těchto sportovních infrastruktur, které však nejsou nebo nemohou být využívány širokou veřejností. ZÁVĚRY: Politika státu v oblasti infrastruktur pro volnočasové aktivity by měla být stanovena bez ohledu na politickou situaci a měla by mít oporu v legislativě. Na národní úrovni by mezi ministerstvy měla existovat konektivita, na místní úrovni by měly úzce spolupracovat relevantní odbory. Otázky politiky by se měly více zabývat možnostmi zlepšování infrastruktur pro volnočasové aktivity pro širokou veřejnost s ohledem na věkové, sociální, etnické i jiné skupiny.
BACKGROUND: The second part of the IMPALA project was based on a wide discussion dealing with the problem of improving the local infrastructure for leisure time physical activity (LTPA) from practical and specifi c points of view that were represented by invited participants from all Czech regions. One of the results of the IMPALA project was the fi nding from some experts that physical environment mostly in adults contribute to an increase of physical activity. AIM: The main aim of this part of the IMPALA project is to present specifi - cally discussed problems from the area of national policy, planning, building, fi nancing and management of the infrastructure for LTPA. METHODS: A discussion was held during a national workshop that was organized in June 2010 at the Faculty of Physical Culture, Palacký University in Olomouc and had a strictly structured programme that was announced and prepared by the main project coordinator. A discussion took place fi rstly in small groups according to each section (planning, building, fi nancing, and management) toward the assessment of a contemporary state and later on proposals whether some improvements exist. RESULTS: The biggest problem connected with planning is the non-existence of external as well as an internal evaluation of a planning process. In the building area the main problem is the accessibility of infrastructures in small villages; social-spatial aspects are not taken into account and building is also infl uenced by land ownership. Financing of local infrastructures for LTPA is very diverse, from public sources to private and also in diff erent business models. Existing fi nancial models are secured by law contracts and taken into account by operating costs. Focusing on management of infrastructures diff ers according to the owner, to fi nancial sources, and to the type of infrastructure. Overemphasizing of top sport means higher allocation of fi nance mostly into sport infrastructures that are not or cannot be used by the wide public. CONCLUSION: The state policy in the sphere of an infrastructure for LTPA should be established regardless of the policy situation and should be supported in legislation. On the national level, there should exist connectivity among ministries, on the local level there should exist close cooperation among relevant sectors. Questions of policy should deal with the possibility for improving the infrastructure for LTPA for a wide public with regard to age, social, ethic and other population groups.
- MeSH
- lidé MeSH
- podpora z veřejných prostředků * MeSH
- pohybová aktivita * MeSH
- primární prevence MeSH
- programy Healthy People MeSH
- velkoměsta MeSH
- volnočasové aktivity * MeSH
- Check Tag
- lidé MeSH
- Geografické názvy
- velkoměsta MeSH